Serum HBsAg cannot distinguish cccDNA activity from integrated HBV DNA expression in chronic hepatitis B virus infection.
BACKGROUND & AIMS HBsAg is currently used as the key serum biomarker to define functional cure of chronic hepatitis B (CHB). Declining HBsAg is often interpreted as evidence of cccDNA elimination or durable transcriptional silencing. However, HBsAg can also be produced from transcriptionally active HBV DNA integrated i...